In-situ polymerization of polythiophene/silicon carbide nanocomposites for gas sensing and optoelectronic devices

Abstract

Silicon carbide (SiC)-reinforced polythiophene (PTh) nanocomposites were synthesized by oxidative in-situ polymerization. The successful inclusion of SiC nanoparticles into the PTh was confirmed by the characteristic peak of Si–C bond around 865 cm−1 in the Fourier transform infrared (FT-IR) spectra. The X-ray diffraction (XRD) patterns demonstrate that the amorphous nature of PTh reduces with the addition of SiC. The intensity of UV–Vis absorbance increased proportionally with filler loading, indicating improved optical properties for PThSiC7 (polythiophene/silicon carbide 7 wt%) nanocomposite compared to pristine PTh. Field emission scanning electron microscopy (FE-SEM) images illustrate the changes in surface morphology of PTh with the addition of SiC and uniform dispersion was observed in PThSiC7. The formation of spherical-shaped moieties was confirmed using transmission electron microscopy (TEM). The shifts in degradation and glass transition temperatures towards higher values were attributed to the enhanced thermal properties of the nanocomposites. Temperature-dependent studies on the electrical and dielectric properties of the samples underscored the excellent conductivity exhibited by PThSiC7 (7 × 10−3 S/cm) with a low activation energy of 0.058 eV. In response to the growing demand for gas sensors, samples were tested to sense ammonia gas, demonstrating that PThSiC nanocomposites were more sensitive than PTh. The controllable optical properties, thermal stability, electrical characteristics, and gas sensing performance of the PThSiC nanocomposites suggest their potential as a promising material for the development of advanced energy storage systems, sensors, and optoelectronic devices.